Intervertebral implants

An interbody implant can comprise a cage and a porous structure. The cage can comprise an anterior segment, a medial segment, a posterior segment and a lateral segment contiguously connected to each other to define an interior space. The porous structure can be located in the interior space and can be bounded by the cage. The porous structure can comprise opposed superior and inferior surfaces exposed through the cage, an internal cavity located in an interior of the porous structure, and a plurality of ports connecting the internal cavity to the superior and inferior surfaces. A superior-inferior stiffness of the interbody implant can be defined by the porous structure. The porous structure can be compressed within a patient by movement of the spine to biologically stimulate bone growth in vertebrae adjacent the interbody implant. The implant can be configured for lateral, anterior and posterior insertion at different spine levels.